1. Field of the Invention
The present invention relates to a recording apparatus using a liquid discharge head for discharging a liquid such as ink and performing recording on a recording medium.
2. Description of the Related Art
As for a recording apparatus using a liquid discharge head such as an inkjet recording head, for example, a serial scan-typed inkjet recording apparatus (it will be called as a recording apparatus below) is known. This recording apparatus performs recording by reciprocally moving a liquid discharge head (hereinafter referred to as a recording head) on a recording medium.
A general configuration of the serial scan-type recording apparatus will be described as an example with reference to FIG. 10.
The serial scan-type recording apparatus performs recording by repeating an operation for discharging ink toward a recording medium from a discharge port of a recording head, and an operation for conveying the recording medium in a sub scanning direction intersecting with the main scanning direction in which the recording head is reciprocally moved. In FIG. 10, the main scanning direction is illustrated with an arrow A, and the subs-canning direction is illustrated with an arrow B.
The recording apparatus mounts the recording head on a carriage 4001 and performs recording by reciprocally moving the carriage 4001 in the main scanning direction A. In a standby area C which is a home position, a cap member 5000 is provided. The cap member 5000 seals the discharge port of the recording head to prevent ink within the discharge port from drying when recording is not performed. A recovery mechanism for maintaining reliability of ink discharge is also provided, and an installation area for the mechanism is secured in the recording apparatus.
A particular configuration of the recording head will be described with reference to FIG. 11, using an example of a recording head discussed in U.S. Pat. No. 6,910,759.
The recording head illustrated in FIG. 11 is a so-called cartridge-type recording head detachably mounted on a carriage of a recording apparatus main body.
The recording head has a recording element unit 41 including a recording element substrate 48, a supporting substrate 47 provided with a recording element substrate, a wiring tape 43 for transmitting an electric signal to the recording element substrate, and a wiring substrate 42 provided with a contact pad 42 for electrically connecting to a main body.
The recording head includes independent ink tanks (not illustrated) of, for example, four colors such as black, cyan, magenta, and yellow. These ink tanks are independently and detachably attached to an ink supply unit 40 respectively.
When the recording head is attached to the recording apparatus, the contact pad 42a arranged on the wiring substrate 42 contacts a contact pin attached in a main body carriage so as to electrically connect the recording apparatus to the recording head. At this time, the wiring substrate 42 receives repulsion from the contact pin attached to the carriage. Therefore, in order to suppress deformation of the ink supply unit 40 or prevent decrease of accuracy with respect to each contact reference when the contact pad 42a contacts the contact pin at a time of attaching the recording head to the carriage, the contact pad arranged on the wiring substrate is disposed at a center part of the ink supply unit in a moving direction of the carriage.
A center of the recording element unit 41 in the moving direction of the carriage (a center of the supporting substrate 47) is provided at a position deviating from the center of the ink supply unit 40. In addition, the recording element unit 41 is provided at a position corresponding to the cap member 5000. The cap member 5000 contacts the recording element unit 41 so as to seal the discharge port.
Therefore, an electric connection portion of the wiring tape 43 and the wiring substrate 42 is attached to a position deviating from the center of the wiring substrate 42, which is also a center of the ink supply unit 40. Thus, the wiring tape 43 has a rectangular shape to connect the wiring substrate 42 to the recording element substrate 48 at a shortest distance so that wiring resistance of the wiring tape 43 does not become too large and a number of produced pieces does not decrease.
In recent years, in order to increase a number of ink tanks for multi-color inks for the purpose of acquiring a high quality image and decrease exchange frequency of ink tanks, the capacity of one ink tank has been increasing. Further, even the capacity of the ink tank is same, an attempt is made to decrease a height of the ink tank and enlarge its width so as to miniaturize the recording apparatus in the height direction.
Therefore, the size of the ink supply unit including the ink tanks tends to enlarge in the main scanning direction (an A direction in FIGS. 10 and 12A) as illustrated in FIG. 12B compared with a conventional configuration illustrated in FIGS. 11 and 12A.
When the ink supply unit enlarges, that is, when the recording head enlarges, an area of the recording apparatus body in the side where the standby area C is not provided must be enlarged as illustrated in FIG. 12B, which causes an enlargement of the recording apparatus.
In order to prevent the enlargement of the recording apparatus, as illustrated in FIG. 12C, the center of the supporting substrate 47 can be displaced from the center of the ink supply unit 40, which corresponds to the cap member 5000, without changing the position of the cap member 5000 in the standby area C of the recording apparatus.
As described in FIG. 11, by arranging the center of the electric connection portion of the wiring tape 43 and the wiring substrate 42 at a position displaced from the center of the wiring substrate 42, the center of the supporting substrate 47 is located at a position displaced from the center of the ink supply unit 40 in the conventional apparatus.
However, in the configuration illustrated in FIG. 11, an amount of displacement between the center of the ink supply unit 40 and the center of the supporting substrate 47 depends on a displacement amount between the center of the ink supply unit 40 and the center of the electric connection portion of the wiring tape 43 and the wiring substrate 42. Therefore, as illustrated in FIG. 12C, the amount of displacement between the center of the ink supply unit 40 and the center of the supporting substrate 47 cannot be larger than a certain amount, which causes an enlargement of the recording apparatus.